/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 86183
 * Date: 2022-09-18
 * Time: 8:51
 */
public class MySingleList {
    static  class  ListNode{
        public int val;
        public ListNode next;
        public ListNode(int val){
            this.val = val;
        }
    }
    public ListNode head;
     public void addFrist(int data){
         ListNode node = new ListNode(data);
         node.next = head;
         head = node;
     }

//    //尾插法
    public void addLast(int data) {
        ListNode node = new ListNode(data);
        ListNode cur = head;
        if (cur == null) {
            this.head = node;
        } else {
            while (cur.next != null){
                cur = cur.next;
            }
            cur.next = node;
        }
    }
//    //任意位置插入,第一个数据节点为0号下标
    public void addIndex(int index,int data) throws indexWrongFulException {
         if(index < 0||index >size()){
             throw new indexWrongFulException("index位置不合法");
         }
         if(index == 0){
             addFrist(data);
             return;
         }
         if(index == size()){
             addLast(data);
             return;
         }
         ListNode node = new ListNode(data);
         ListNode cur = toFindindex(index);
         node.next = cur.next;
         cur.next =node;
    }
    private ListNode toFindindex(int index){
         ListNode cur = head;
         while (index - 1 != 0){
             cur = cur.next;
             index--;
         }
         return cur;
    }
//    //查找是否包含关键字key是否在单链表当中
    public boolean contains(int key){
         ListNode cur = head;
         while (cur != null){
             if(cur.val == key){
                 return true;
             }
             cur = cur.next;
         }
         return false;
    }
//    //删除第一次出现关键字为key的节点
    public void remove(int key){
         if(head == null){
             System.out.println("该链表为空");
             return;
         }
         if(head.val == key){
             head = head.next;
             return;
         }
         ListNode cur = toFindKey(key);
         if(cur == null){
             System.out.println("不存在该数据");
             return;
         }
         ListNode del = cur.next;
         cur.next = del.next;

    }
    private  ListNode toFindKey(int key){
         ListNode cur = head;
         while (cur.next!= null){
             if(cur.next.val == key){
                 return cur;
             }
             cur = cur.next;
         }
         return null;
    }
//    //删除所有值为key的节点
    public void removeAllKey(int key){
         if(this.head == null){
             return;
         }
         ListNode prev = this.head;
         ListNode cur = this.head.next;
         while(cur != null){
             if(cur.val == key){
                 prev.next = cur.next;
                 cur = cur.next;
             }else {
                 prev = cur;
                 cur = cur.next;
             }
         }
         if(this.head.val == key){
             this.head = this.head.next;
         }
    }
//    //得到单链表的长度
    public int size(){
         ListNode cur = head;
         int count = 0;
         while (cur != null){
             cur = cur.next;
             count++;
         }
         return count;
    }
    public void display(){
        ListNode cur = head;
        while (cur != null){
            System.out.print(cur.val+" ");
            cur = cur.next;
        }
        System.out.println();
    }
    public void clear(){
         this.head = null;
    }
    public ListNode reverseList(ListNode head) {
       if(this.head == null){
           return null;
       }
       if(head.next == null){
           return head;
       }
       ListNode cur = head.next;
       head.next = null;
       ListNode curNext;
       while (cur != null){
           curNext = cur.next;
           cur.next = head;
           head =cur;
           cur = curNext;
       }
       return head;
    }
}
